My favourite is missing from the list: \usepackage{needspace}.
LaTeX' page-breaking algorithm gets it right most of the time but sometimes a bit of help makes it even better, i.e. a
\needspace{4\baselineskip}
\subsection{Something}
Lorem ipsum ...
tells TeX to insert a pagebreak here if there's fewer than 4 lines of text left on the page, otherwise just carry on. Unlike \pagebreak[n], this is not optional.
\usepackage{refcheck} belongs in everyone's toolbox as well.
LaTeX' page-breaking algorithm gets it right most of the time but sometimes a bit of help makes it even better, i.e. a
tells TeX to insert a pagebreak here if there's fewer than 4 lines of text left on the page, otherwise just carry on. Unlike \pagebreak[n], this is not optional.
\usepackage{refcheck} belongs in everyone's toolbox as well.